take screenshot of active window c# code example
Example: c# windows grab screenshot
private Bitmap GetSreenshot()
{
Bitmap bm = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);
Graphics g = Graphics.FromImage(bm);
g.CopyFromScreen(0, 0, 0, 0, bm.Size);
return bm;
}